1. Technical Field
The invention relates to an improved cutter bit. More particularly, the invention relates to shaft mounted rotary cutter bits of the type mounted in rotary woodworking machines. Specifically, the invention relates to multi-edged rotary cutting bits having multiple profiles on a single bit.
2. Background Information
It is customary in building construction, as well as the construction of furniture and cabinetry to impart decorative profiles upon the wood. Moreover, many joints are created by imparting a variety of profiles on the wood to create stronger joints, as well as to provide increased surface areas for glue contact at the joint. Regardless of the reason for imparting a profile on the wood, the profile may be created in one of two methods. Hand planes may be utilized, which planes have a cutting knife shaped with a negative of the profile to be imparted on the wood. However, such planes are expensive, inaccurate and require significant skill to utilize. As such, many power tools have been specifically designed to impart a desired profile onto a workpiece while existing tools have been modified to allow those tools to also impart the desired profile.
While many such tools exist, routers and rotary cutters are by far the most prevalent. Rotary cutters include a motor which rotates a chuck at a predetermined or variable speed. When the rotary tool operator wishes to impart a given profile onto a workpiece, the shank of the a cutter bit having the desired profile is installed into the chuck. When the motor is activated, the cutter bit will rotate with each blade of the bit removing material from the workpiece creating the desired profile.
As woodworking becomes increasingly popular in the hobby market, and competition increases in the building trades, a significant number of cutter bits, each presenting a corresponding profile, have been developed. In some markets, the need to change bits often, or alternately, to utilized bits which have complimentary shapes, has also been developed. More particularly, router bits have been developed which include multiple profiles so that the need to change router bits is substantially reduced. These bits are often called multi-profile bits and substantially increase the usefullness of the bit, while reducing the amount of time needed to change router bits within the rotary tool.
More particularly, when a finish carpenter or trim carpenter must switch cutter bits, a significant amount of time is expended when the first bit must be removed from the rotary tool and replaced with a second bit. If the bit is to be entirely removed from the cutter, often the collet must be significantly loosened, thus increasing the amount of time necessary to exchange bits within the rotary cutter tool. Further, on a busy construction site, tools are often stored at a position far away from the area where work is actually taking place, which increases the amount of time it takes a carpenter to retrieve the required bit for use on the job site. Additionally, as multiple bits are utilized on a job site, the risk of loss of the bit is much greater, thereby increasing project costs, as the carpenter will not only have to repurchase the bit, but will loose time as a result of the lost cutter bit. For these reasons, bits with multiple profiles have fallen into favor so that a single bit may be utilized to impart multiple profiles on a common workpiece. Often times, the bit may simply be adjusted within the router, or alternatively, the base of the router may be moved relative to the bit in order to change that portion of the bit which is engaged with the workpiece, thereby changing the profile imparted on the workpiece.
The benefits of multi-profile bits as set forth above are obvious, these bits are often not appropriate to use with smaller routers known as rotary cutter tools, which have much less power to spin large multi-profile bits. The benefit of a single bit with multiple profiles cannot be understated, given the cost savings and convenience of such bits, but given that smaller rotary cutter tools have a relatively small base and are often held in one hand, the use of large bits creates a number of safely concerns, not the least of which is that a large bit and a very small tool may be difficult to control, creating an unsafe condition. It would thus be valuable to have bits having multiple profiles such as those that are used with larger commercial routers, but which solve the safety concerns associated with bits of this type.
Objectives of the invention include providing a lightweight cutter bit.
A further objective of the invention is to provide a cutter bit wherein the bit includes multiple profiles on a single bit.
A still further objective is to provide a cutter bit having a body which may be flipped end to end with each end of the body providing alternative cutter profiles.
A still further objective is to provide such a cutter bit which is of simple construction, which achieves the stated objectives in a simple, effective and inexpensive manner, which solves problems and satisfies needs existing in the art.
These and other objectives and advantages of the invention are obtained by the improved cutter bit, the general nature of which may be stated as including a rotary cutter bit for imparting a profile to a workpiece comprising:
a body formed with an axial length and a first end and a second end, a first cutting knife mounted to the body adjacent the first end and second cutting knife mounted to the body adjacent the second end.